Add an "always" callback

[Rycochet]

Currently the "complete" option doesn't fire if the animation is stopped for whatever reason - having an "always" gives the ability to run a function even if you cancel the animation early.

[julianshapiro]

What if always was a boolean value? If true, fire complete even if the animation stops.

Would this be a cleaner solution than having two competing callback options (both complete and always). Thoughts?

[Rycochet]

I think that the Promises support in #143 covers this nicely - so unless you want to add a specific callback I'd say close this :-)

[julianshapiro]

Having a promise returned necessitates using the utility function, and so always still has a purpose (although certainly a lesser one).

I'll leave this thread open to see who else comes by and asks for this. Thanks for everything, Robin.

[julianshapiro]

I'll close this for now. We'll see if anyone else requests this.